1 #include<bits/stdc++.h>
2 using namespace std;
3 typedef long long ll;
4 typedef double db;
5 #define INF 0x3f3f3f3f
6 #define _for(i,a,b) for(int i = (a);i < b;i ++)
7 #define _rep(i,a,b) for(int i = (a);i > b;i --)
8 inline ll read()
9 {
10 ll ans = 0;
11 char ch = getchar(), last = ' ';
12 while(!isdigit(ch)) last = ch, ch = getchar();
13 while(isdigit(ch)) ans = (ans << 1) + (ans << 3) + ch - '0', ch = getchar();
14 if(last == '-') ans = -ans;
15 return ans;
16 }
17 inline void write(ll x)
18 {
19 if(x < 0) x = -x, putchar('-');
20 if(x >= 10) write(x / 10);
21 putchar(x % 10 + '0');
22 }
23 int n,mod;
24 int dp[2][6002];
25 int main()
26 {
27 n = read(), mod = read();
28 dp[0][2] = 1;
29 _for(i,3,n+1)
30 _for(j,2,i+1)
31 dp[i&1][j] = (dp[i&1][j-1]+dp[(i-1)&1][i-j+1])%mod;
32 int rnt = 0;
33 _for(i,2,n+1)
34 rnt = (rnt+dp[n&1][i])%mod;
35 write((rnt<<1)%mod);
36 return 0;
37 }
